The present invention generally relates to materials science research, and specifically, to combinatorial (i.e., high throughput) materials science research directed toward the identification and/or optimization of new materials. The invention particularly relates, in preferred embodiments, to apparatus and methods for optimizing chemical reaction systems, such as chemical reaction systems involving heterogeneous catalysts.
In recent years, significant efforts have been extended toward developing parallel systems, such as parallel reactors, for the purpose of screening different materials, such as heterogeneous catalysts, for particular properties of interest, such as catalysis. U.S. Pat. No. 5,985,356 to Schultz et al. discloses synthesis and screening arrays of materials in parallel for catalysis, and U.S. Pat. No. 6,063,633 to Willson discloses parallel flow reactors, and parallel screening techniques (e.g., thermography, chromatography, etc.) for evaluating catalysis. A substantial portion of such effort has, however, focussed on apparatus and methods for evaluating compositional space of the materials (e.g., heterogeneous catalysts) of interest, while only a relatively small portion of such effort has been directed toward apparatus and methods for evaluating other parameter spaces—in addition to compositional space. More specifically for example, in the context of heterogeneous catalysis research, only limited attention has been focused on the development of apparatus and methods for high-throughput, parallel optimization of important parameters such as catalyst (or catalyst precursor) processing conditions and reaction conditions.
A number of parallel flow reactors are known in the art. For example, PCT application WO 98/07206 (Hoechst) discloses a parallel flow reactor said to be useful for evaluating chemical reactions using minaturized reactors. U.S. Pat. No. 6,149,882 to Guan et al. discloses, among other facets, a parallel flow reactor for screening of heterogeneous catalysts in which feed flow is controlled using flow restrictors such as capillaries to obtain substantially the same flow in each of the reaction channels. More recently, WO 00/51720 (Symyx Technologies, Inc.) discloses a parallel flow reactor design that addresses several significant technical challenges, including flow distribution challenges for parallel screening of catalysts in very large numbers. Other references, including WO 97/32208 (Technology Licensing Co., Ltd.), DE 19809477 (Schuth), WO 99/41005 (BASF) and DE 19806848 (BASF) likewise disclose parallel flow reactor configurations. Various of the aforementioned references contemplate control of the reaction temperature in the parallel reactors, including for example, applying a thermal gradient across a plurality of reactors to investigate temperature effects on a reaction of interest. Typically, thermal control is effected for all of the reaction vessels, collectively, or for a subset of the reaction vessels as modules or zones.
These and other reactor designs known in the art do not, however, specifically address approaches or contemplate apparatus for investigating and/or optimizing reaction temperature—simultaneously and independently—in relatively closely-packed, highly parallel reactors. As reactor dimensions become reduced, and as the spatial density of reactors increases, significant thermal cross-talk between reaction vessels can be a substantial obstacle for achieving simultaneous and independent temperature control in such reaction systems.
Hence, there remains a need in the art to overcome such deficiencies, and to provide for parallel flow reactors having robust temperature-control capabilities for systematically investigating and/or optimizing chemical processes with respect to temperature.